Work support for grinding machines and the like



Sept. 13, 1949. M. FAIREST ETAL 2,481,918

WORK SUPPORT FOR GRINDING MACHINES AND THE LIKE Filed Oct. 13,, 1947 5 Sheets-Sheet l Inventors flM#-M .0? 0.0 \w w m 3 Sept. 13, 1949. M. FAIREST ETAL WORK SUPPORT FOR GRINDING MACHINES AND THE LIKE Filed Oct. 15, 1947 3 Sheets-Sheet 2 FmL Sept. 13, 1949. M. FAIREST ET AL 2,481,918

WORK SUPPORT FOR GRINDING MACHINES AND THE LIKE Filed Oct. 15, 1947 s Shets-Sheet 3 27., lze 1 25 Inventor-r 'w g wfinw y wa @14 44% y Patented Sept. 13, 1949 WORK SUPFQRT FOR cements RE'ACHENES AND THE LIKE' .Morgan Fairest and Derek Howard Fairest, Sheffield, England, assignors to Morgan Fairest, Limited, Sheffield, England Application Gctober 13, 1947, Sei ial N1), 77.95 190? In Great Britain October 12, 1946 6 Claims.

(Granted This invention relates towork supports for grinding and other" machines in' which the work is moved longitudinally relative'to a tool; andhas particular, though not exclusive; reference to work'slides for grinding theblades of table knives, shear blades, and similar articles oi cutlery.

It is usual to grind each side of table knife and similar blades as a separate operation, thegrinding of one side beingeffected by feeding the blade, held edge upwards, lengthwise in an oblique (i. e., non-radial) direction" across one side of a cup-Wheel mounted on a spindle that is out of the normal to the direction offeed; The face of the wheel is hollow to forms conical surface,- which, with the curvature of the face, imparts the desired slightly rounded face to the side ofthe blade. The blade is first fed'inwards clear of the wheel, and is then-moved'into contact with the wheel to begin' grinding-attire neck of the blank adjacent the bolster, and ist-hen Withdrawn outwardly slowly still in cohtact with themes of the wheel until the blade tip hasbeen ground; the blade being twisted'slowlyabout an axis substan to the wheel and hold it to'a definitepath during the grinding stroke.

Another object is to provide a mechanisrn in which there is not only little likelihood of wear, but also negligible effect of wear on the ac curacy of the path followed during the grinding stroke.

A further object is to enable the blade to be retracted quickly and automatically at the end ofthe grindin stroke.

Further objects include the provision of simple adjustment of stroke in" accordance with the length of the blade to be ground.

The invention comprises a work support including a table"longitudihally movable with-respect to a tool, a workslid'ecarriedby the table and guided so as to be able to slide transversely" 032' the table", a stop adapted tdbe encountered-near the end of one movement ofthe table, cam-means'-- under theprovisiohs of s'e.--14-,act oi" Marchz, 1927; 357 0. GA 5) 2 of the table; and-a fuitl'iefstep adapted to be encountered-near the-end of thereverse movement of the table to eifectareturn movement of the slide-transvislyt the table. The Work may be operated on by a gf'ihding wheel, milling cutter, or the like; but iri thefollowing description, reference willibe mainly to t'he use of a-wheel for grindihgthe werk l- Preferably; the cam is carriedby a-push-rod movable longitudinally the table and adapted to engage the first stopytheeunswram engaging a follower oh the worisslidd The push-rod may, in addition"to prvidihg the lift required to move the slide the-desired amount transversely of the tab1e, -provide a locking surface, which, by continuedmovement'otthe push-rod relative to thetable, prevents ietiirn movement of the slide, thus aispensingwithseparate look-- ing mechanism; The 'seondstop returns the push-rod to-i'elas'etlie s1it1'e, theretur'n of the slide preferably 'beiiig efiected by a spring energised duringsthe movement "of the slide under the cam-action; The spring serves to hold the slide firmly"against-tlie locking surface of the push-rod, whitenes -languishing surfaces engaging' corresponding terraces: in the work table (e. g. inot'iesile" or a slotwhith the push r'od slides) and thus provides a rigid support for the positioningof the woi-k' slide while the latter is carrying the blaflliii 'g'i-ihdihgcontact with the wheel. When the puSlFrod-is-returned by'the second step,- i the spring r'n'ove's' :the slide quickly away from the wheel Although the'use osa-push -rod-with a cam to move the slide transverselyof the table enables the slide to bemoved iii any desir'ed direction across the table; was preferred-mo mount the slide onguidesinclihed aerossthe table, so as to provide, for any: given width of table, guiding surfaces longer than; the width;

The ihventionwi'll now be' described in greater detail with reference td-a grinding machine in which the eam adtion for-moving the slide transversely to the tableis provided by'a push-rod;-

In the accompanying drawings Figure l is a plaid new, partly in section, of a grinding machine setior the grinding of table and s'i-in-ila i kiiiiiml Figures 2, 3, and sgare views similar to Figure 1 at difierent stages in the operating cycle;

Figure 5 is aplan view of the workslide and moving table-ifi gratei detail and to a larger scale; artly insectlon; I V

Figure o-isa sectional elevatientaken on the operable by thes'top-to move-the slide transversely line 6 6 oi Figiii'ei w V Figure 7 is an end elevation of Figure 6, showing also the work holder;

Figure 8 is a fragmentary section on the line 88 of Figure Figure 9 is a large-scale section through the blade of a knife in the work holder, the section being taken on the line 9-9 of Figure 4;

Figure 10 is a similar view to Figure 9, but looking in the reverse direction, showing how the blank is held on the work-holder;

Figure 11 is an elevation on the line II-II of Figure 10; and

Figure 12 is a diagram showing the approach of the blank to the wheel.

Referring particularly to Figures 1 and 7, a table I2 is mounted on long slide ways I3 carried by the machine bed I4 so as to be movable to and fro in a direction generally transverse to the axis l5 of a cup wheel I6.

A work slide I1 is carried on the upper face of the table I2, and to it is secured an angle bracket I8, from which pivot brackets I9 protrude towards the wheel I6 to receive pivot pins at each end of a work holder 2| comprising a long block 22 to the face of which is secureda pad 23. Below one end of the pad, a ledge plate 24 protrudes to support the back edge of a knife blade 25 near the bolster 26, the tang 21 of the blade being engaged in a bayonet slot 28 (Figures 10 and 11) of a pin 29 protruding from the block 22. An arm 36 of the work support 2| carries a roller 3| resting on a former bar 32, adjustable (as will be described later) to twist the support 2|, if desired, slowly about the pivots 2|] as the support is carried by the table I2 across the wheel I6.

The axis I5 of the wheel I6 is shown inclined (at about 10) to the normal to the path of the table I2, and the face 33 of the wheel is inclined inwards to the same amount so as to lie parallel to the path of the table. For some purposes the axis may be normal or inclinedin the opposite direction to the normal, but in all cases the movement of the table I2 of themachine shown is used to carry the work across the left-hand side 34 of the wheel, with an idle movement in one direction and a grinding movement in the reverse direction.

The machine may, however, be constructed with the table and work-holder reversed with respect to the wheel, in which case the work is carried across the right-hand side of the Wheel, to enable the other side of a blank to be ground; and, in fact, machines are generally used in pairs, one left-hand and one right-hand.

Referring now to Figures 5, 6, and 7, it will be seen that the table I2 has two V-grooves 35 running at 45 from right to left from the front to the back of the table, and the slide I! has two corresponding but inverted grooves 36. In the grooves 35, square-sectioned blocks 31 are secured by screws 38, and the slide I1 is held on to the blocks 31 by washers 39 retained by lock nuts 40 on pins 4| projecting from the table I2 and passing through slots 42 in the slide parallel to the grooves 35, 36. A plunger 43, also parallel to the grooves 35, 36 is urged by a spring 44 into contact with an abutment 45 protruding from the table I2 so as to urge the slide I1 towards the front of the table |2.

A hydraulic cylinder 46 carried by the machine bed I4 runs parallel to the length of the table I2 and the piston is connected by a piston rod 48 to a lug 49projecting downwardly from the right-hand end of the table |2. Oil admitted to one or other of the ports 56 in turn, through 4 pipes 5| connected to suitable reversible valvegear (not shown), causes the table to move to and fro with any desired length of stroke.

Running lengthwise of the table I2 is a parallel slot 52, passing to the right-hand end of the table and breaking through a recess 53 near the middle of the table. A push-rod 54 closely fits the slot and a lateral arm 55 of the rod protrudes through the recess 53 beyond the front of the table. Opposite the arm 55, the rod is notched at 56 to form a land 51 leading by a cam slope 58 to the edge 59 of the rod. A follower roller 68 depends from a pin 6| secured to the slide I'I into the recess 53 and is urged into the notch 51 by the plunger 43, so that the roller is forced into contact with the rod 54.

The end of the rod 54 carries a plate 52 facing an adjustable stop 63 on a bracket 64 extending upwards from the machine bed I4. The plate 62 itself carries an adjustable stop 65 facing the edge of a cover plate 66 secured to the table I2 over the rod 54. An adjustable stop 61 carried by a bracket 68 from the machine bed I4 lies parallel to the length of the table I2 in line with the lateral arm 55 of the rod 54.

The sequence of operations is shown in Figures 14:

In Figure 1, a knife blade 25 in the work holder 2| is moving to the right under the admission of oil through the left-hand port 55 of the cylinder 46. The roller 60 bears on the land 5l in the notch 56 of the push-rod 54, the slide II thus lying in its nearest position to the front of the table I2. In this position, the blade 25 lies clear of the side 34 of the wheel I6.

As the table I2 nears the right-hand end of its stroke the plate 62 on the end of the push-rod 54 meets the stop 63, and the push-rod is prevented from further motion to the right. The table I2 continuing its motion to the right, the roller 66 is caused to ride up the cam slope 58 of the nowstationary rod 54 and on to the edge 59 of the rod. The slide I1 carrying the roller 66 is forced to follow the movement of the roller, and is thus pushed towards the rear of the table I2, by an amount equal to the lift of the cam, the slide moving along the guide blocks 31 in the grooves 35, 36. During this movement, the spring 44 is compressed on to the plunger 43.

On reaching the full lift of the slope 58, the roller 60 comes to rest on the edge 59 of the bar 54, and remains urged against the bar by the pressure of the plunger 43, the whole length of the bar resting in the slot 52 providing a rigid backing against the thrust of the slide I'I transversely of the table I2.

When the cover plate 66 reaches the stop 65,

the right-hand motion of the table I2 ceases, and

at this moment the outside diameter of the wheel I6 makes grinding contact at the neck of the blade 25, i. e. against the bolster 26, the blade having been brought against the face of the wheel by the movement of the slide I! to the rear of the table |2. This is the position shown in Figure 2. The operation of the cylinder 46 reverses, and the table I2 moves to the left, carrying with it the slide H, which is locked to the table by the pressure of the roller 60 on the edge 59 of the rod 54.

The movement of the work up to this point may be closely followed by reference to Figure 12:

The blank (blade 25, bolster 26, and tang 21) as shown in full lines is moving to the right (arrow a) as in Figure 1, with the blade 25 parallel to, but clear of, the face 33 at the left-hand a encies continues to move bathe? amount. shown by the chain-line containing theaarroim b;- .and 'thes-cam 58 pushes: the slide it! randrthierefore. the: blank) in a. 45 direction as showncby the chain-line neck HitlyingtagainstzthB :ra-diused'edge l6? of the wheel, asmayebe adjilstedzawith precision by means of'the stopl A ti'zfi iis' point, the table I2 is reversed by the cylinder 46 (arrow e), and grinding of the side oi thebl'ade 21") continues from thecompletednecktather-tip the. blade until the position of Figure 3 isreached- During the grinding stroke, the pressure of the wheel keepsthe reanside -of theblade firmly against the pad 23, with thevback edge of the blade resting; on the ledge 24.v The accurate guiding of the tablejl by the. long slide ways I3 and the pressureof the spring through the slide H- to the long edge: (Kathe slot 52 containingthe'push-rod,51.6118111881 the blade fol lows: an accurate .line across. theitwheel 1 6 which may. be repeated, withequal accuracy if.ii'.;.l3110.ve necessary to send the blade a further time across the wheel. As a result, a highly finished ground surface is produced that calls for the minimum amount of glazing in a subsequent operation, as is usual with table and similar knives.

When the position in Figure 3 is reached, the stop 61 meets the arm 55 to push the rod 54 to the right (relatively to the moving table 12), thus carrying the cam slope 59 under the roller 68. The pressure of the plunger 43 causes the roller 60 to push the rod 54 to the right (there being nothing to oppose this movement of the bar), and the roller 60 reaches the land 51 with a snap action. The slide l'l thus moves quickly towards the front of the table I2 (Figure 4) and the blade 25 is withdrawn from the wheel, with no delayed contact that might mar the ground surface of the tip of the blade.

In a short continued motion of the table I2 to the left (Figure 4), the ground blade is removed and replaced by a fresh blank, or, if necessary, the blade is left to undergo a further grinding cycle. Reversal of the operation of the cylinder 46 again brings the mechanism to the position shown in Figure l. The width of the recess 53 provides the necessary freedom of movement of the arm 55 relative to the table l2, the right-hand side of the recess limiting the amount by which the push-rod moves relatively to the table. The three stops 63, 65, and 6? enable the positions of the ends of the strokes and the rearward and forward movements of the slide H to be determined with precision in accordance with the length of the blade 25, in conjunction with the reversing mechanism for the supply of oil to the cylinder 46.

As the slide I1 is carried to the left, the roller 3! moves along the former plate 32. This plate is adjustable about a pivot 69 (Figure '7) on a stem 19 by a setting screw H, out of line with the pivot 69, and is clamped by a nut 12 in adjusted position. The stem 10 is carried in a tubular mounting 13 on the machine bed l4, and

is; adjustablefor 1 height by; a screw 14: and

angle by a screw 1-5.; For grinding table and similar; knives; the plate 32 is set, by the adjustments.jnstidescribed,

asgrinding proceeds from, neck o. p; Q-aIIQW forthe varying, taper; of the. blade arisingfrom; the gradual thinning of, thebackedge of-the' The: slight blade in the direction ofthe, tim.

l0 outward curvature of the-sectioniof the-blade (inadicated in: Figure 9'); arises from, the! p en er tion of the face of the-blade. to-the cup-wheel;

along a line that does notv intersect the. axisaof thewheel, and from the inward inclinationot.

the face of-the wheel.

During, the whole stroke-, the bladeremainsr pressed to the pad 23 by thepressure; of the wheel l6, and. the blade is solidly supported by; the thrust carried through the roller' 60. and;

push-rod E ite the table t2,- and! thence" to. the long slide ways I3. There is plittle likelihood ofwear in these parts, and shouldwear. take-place, the steady pressure towards the front of the machine ensures that the'wor-k f-ollowsa straight and consistent path across the-wheels When one side of a; blade has been ground in,

a machine as in Figure 1,. the other. face is,- ground in a machine with thepartsreversed; the

blank being inserted at'the right and g-roundabythe'right-hand side of thewheeh.

For grinding other formsof cutlery; the axis of the wheel may be normal to the direction of motion of the table, the side of the blank then being ground perfectly flat, or it may be reversed in inclination (as compared with Figure 1) to produce a hollow-ground surface, e. g. for shear blades. Though these different positions of the axis of the wheel relative to the table may be fixed in any one machine, it will be evident that they may be provided in a single machine by pivoting the whole of the part of the machine bed carrying the slide way, table, work slide, cylinder, stops, and associated mechanism in relation to the wheel, the position of the pivot being substantially in line with the operative portion of the face of the wheel, as indicated at 16 in Figure 1. Alternatively, the wheel-mounting may be adjustable about a similarly-positioned pivot.

Figures and 11 show how the blade is held against the pad 23 and on the ledge 24. A screwed shank Tl secures the pin 29 protruding from the block 22 of the work support beyond one end of the pad 23. The pin has the inclined slot 28 in its face breaking into a hole 18 parallel to the length of the pad 23, the slot 28 and the hole 18 forming a bayonet joint. The tang 21 is passed through the slot 28 with the blank inclined at a corresponding angle, and when the tang enters the hole 18, the blank is able to drop parallel to the pad 23 until the back edge rests on the ledge 24, there being sufiicient freedom of the tang in the hole '18 to permit the blade 25 to be pressed by the wheel against the pad 23.

The machine has been described with the wheel axis l5 horizontal, and the work movable in a horizontal direction towards and away from the wheel, but it will be understood that the wheel may be mounted otherwise than horizontally; thus it may have a substantially vertical axis, and the work slide may be arranged to move the work towards and away from the wheel in a vertical direction.

The work support may be used in other mato twist thework holder; 2| steadily and slowly;

7. chines with a to-and-fro movement of the work. e. g. milling machines and planing machines.

What we claim is 1 a -1. In a grinding or other machine, a machine bed, a table movable longitudinally on the bed with respect to a tool, hydraulic means to impart a longitudinal stroke to the table, a work slide carried by the table and guided so as to slide transversely of the table, a push-rod movable with the table and having a positively limited movement longitudinally of the table, a cam on the push-rod adapted to move the work slide transversely of the table during such limited movement, stops on the bed to engage the pushrod near the ends of its movement with the table, and an adjustment for at least one of the stops to provide any length of stroke of the table within the maximum stroke of the hydraulic means after allowing for the limited movement of the push-rod, the positive engagement of the push-rod with the table at the ends of such limited movement determining the stroke of the table against the urge of the hydraulic means.

2. In a grinding or other machine as in claim 1, an arm projecting laterally from the push-rod, one of the stops being positioned to one side of the push-rod to engage the arm.

3. In a grinding or other machine as in claim 1, a recess in the table, and an arm on the pushrod projecting laterally through the recess, one of the stops being positioned to one side of the push-rod to cause the arm to perform its limited movement determined by engagement of the arm with one side of the recess.

4. In a grinding or other machine as in claim 1, means for adjusting one end of the limited'movement of the push-rod independently of the stops efiecting such movement.

5. In a grinding or other machine as in claim 1, guides inclined across the table, and a spring urging the Work slide along the guides in opposition to the camon the push-rod.

6. In a grinding or other machine as in claim 5, inclined V-grooves in the table, square-sectioned blocks secured in the grooves to form guides, and registering inverted grooves in the work slide..

MORGAN FAIREST. DEREK HOWARD FAIREST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

